A group of police and crime commissioners urge tougher penalties for supply and possession.
A group of Conservative police chiefs is calling for cannabis to be reclassified from a Class B to a Class A drug.
This would put it in the same category as heroin, cocaine and ecstasy.
It would mean tougher penalties for possession, and potential life sentences for suppliers and producers.
The policy is being proposed by Tory police and crime commissioners, who are elected to hold police forces to account in England and Wales.
They are not in charge of criminal law or police operations – but they can be an influential voice on policy.
At the Conservative Party conference in Birmingham, a group of them will argue new health data on cannabis makes the case for re-evaluating penalties.
They will say it is “time we realised that it is not just a little bit of weed”.
The Home Office said there were no plans to reclassify cannabis.
And cannabis campaigners have dismissed the idea as “crazy” and “dangerous”.
But David Sidwick, the Police and Crime Commissioner for Dorset, said that cannabis was “driving harm” in communities.
“We’re seeing it because it’s a gateway drug. If you look at the young people in treatment, the number one drug they are in treatment for is cannabis.”
Mr Sidwick, who used to work in the pharmaceutical industry, claimed that a “wealth of new data” on the drug’s effects on health had come to light, which merited a “re-evaluation”.
He also said that enforcement needed to go hand-in-hand with rehabilitation and education, but that reclassifying cannabis would provide clarity.
“There are so many crimes linked to drugs that, actually, by addressing this, by giving us this clarity, it makes it clearer for our police to be able to do what they need to do.”
The penalties for possession of a Class A drug include an unlimited fine and up to seven years in prison.
Suppliers and producers can be sentenced to life.
Sentences for Class B drugs are up to 5 years for possession and up to 14 years for supply or production.
Peter Reynolds, the President of CLEAR, which campaigns against the prohibition of cannabis, said the proposal to reclassify it was “completely crazy.”
He said the Commissioners were “promoting ideas which will increase crime, violence and child exploitation”.
“The idea of doing more of the same as the past 50 years, which has quite obviously dramatically failed, is ridiculous. The only people who want this are ignorant politicians and the people who sell illegal drugs, I’m crystal clear about that.”
In a recent letter to police forces, Home Secretary Suella Braverman said that drug-fuelled crimes were not being taken seriously enough.
A spokesperson for the Home Office said: “There are currently no plans to reclassify cannabis, which is controlled as a Class B drug in the UK on the basis of clear medical and scientific evidence of its harms.”